But it's a year before your risk for heart attack is half that of a smoker's. Five years before risks of mouth, throat, esophageal and bladder cancer are cut in half, and a full ten years before your risk of dying from lung cancer drops to half that of a smoker.

"Given the knowledge we have today it's almost foolish to even think about smoking," says Dr. Govindan.

If you're young, quitting now will give you years of good health to look forward to. But putting down the cigarettes at any age can give you a quality of life you won't otherwise have.

"If you've been smoking for 20 or 30 years still it's never too late to stop smoking," says Dr. Govindan.